Athletic shoes, in particular running shoes, are typically designed to correct for perceived deficiencies in athletes' gaits and encourage running with a neutral gait. In a neutral gait, which is widely considered the ideal running motion, the foot maintains a balanced transition from heel strike to foot propulsion without placing undue stress on the lower leg, including the ankles and feet. Accordingly, certain running shoes are designed varying degrees of support on the medial side of the shoe to help guide or control mild, moderate, or severe overpronation (i.e., the motion of the foot rolling excessively inward through the foot strike). Similarly, other types of running shoes are designed with varying degrees of support on the lateral side to correct for underpronation or supination (i.e., the motion of the foot rolling outward through the foot strike). Still other running shoes are moderately cushioned for shock absorption to encourage a neutral gait.
Gait analysis is often used to characterize an athlete's running motion (e.g., overpronation, underpronation, or neutral pronation) and select a running shoe based on the athlete's gait. Specialty running stores, for example, typically have trained associates that watch athletes run a short distance (e.g., in the store or on a treadmill) to analyze their gaits, and recommend running shoes based on their assessment. Video systems have also been developed that visually record athletes running on treadmills to capture and review the athlete's movement characteristics or patterns while running. The captured data can be used to identify potential concerns with an athlete's gait. Regardless of the manner in which the athlete's gait is analyzed, the objective when selecting a running shoe is to correct for any lower body movement outside of a neutral gait so that the running shoe allows the athlete to run with a substantially neutral gait.